In actual use, at the intermediate station, the packets coming off the conveyor assembly are pushed to the transfer unit by the line of packets travelling on the conveyor assembly; and the transfer unit transfers the packets coming off the conveyor assembly from an extraction location at the intermediate station to an output conveyor.
Known devices of the type described above are not very versatile, and do not adapt easily to varying production requirements, particularly changes in packet size.
Known devices of the above type are also subject to frequent breakdowns and damage, to the packets as a result of jamming caused by poor coordination of the conveyor assembly and transfer unit.
According to a further aspect of the present invention, the conveyor assembly conveys the line of packets at a given travelling speed in a first direction. The device also comprises a feed unit for feeding a succession of packets to the conveyor assembly in the first direction; in actual use, once fed to the conveyor assembly, the incoming packets form part of the line of packets; and the packets forming part of the line of packets are conveyed by the conveyor assembly.
A drawback of known devices of this type is the possibility of gaps forming between successive packets in the lines of packets moving forward from the input station. As a result, the packets are subject to damage, by being allowed too much freedom of movement, and/or have different structural characteristics as a result of different pressure being exerted on the walls of the packets.